Endoscope apparatus and program

ABSTRACT

An endoscope apparatus includes: an imaging portion imaging a subject to generate image data; a designation portion designating a position in an image based on the image data; an image processing portion processing the image data such that an enlarged image obtained by enlarging an image in a second region including the designated position overlaps a first region including the designated position designated by the designation portion; a display portion displaying the enlarged image and the image of the subject based on the image data processed by the image processing portion and displays a cursor at the designated position on the enlarged image; and a measurement processing portion performing measurement on the basis of a measurement position indicated by the cursor by using the image data generated by the imaging portion. The enlarged image displayed on the display portion moves according to movement of the cursor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope apparatus, which performsmeasurement on the basis of image data obtained by imaging a subject,and a program.

2. Description of Related Art

Industrial endoscope apparatuses are used to observe or check insidedamage, corrosion, and the like of a boiler, a turbine, an engine, apipe, and the like. Moreover, among the endoscope apparatuses, there isan endoscope apparatus having a function of measuring the lengths areaand the like using the principle of triangulation on the basis of ameasurement point designated on an image imaged by the endoscope. Thisendoscope apparatus has a plurality of kinds of optical adaptersprepared to observe and check various objects, and a tip portion of theendoscope apparatus can be replaced.

An example of such an optical adapter includes a stereo optical adaptercapable of imaging two subject images of the same subject. Using thestereo optical adapters the length, area and the like of the subject canbe measured by calculating the three-dimensional spatial coordinates ofthe subject using the principle of triangulation on the basis of thecoordinates of left and right optical system distance calculating pointswhen the subject image is captured by the left and right opticalsystems.

FIG. 24 shows a display screen of an endoscope apparatus. A left image901L and a right image 901R corresponding to left and right subjectimages captured by a stereo optical adapter are displayed on a displayscreen 900 shown in FIG. 24. In addition, cursors 902 a and 902 b fordesignating measurement points indicating measurement positions aredisplayed on the display screen 900. The user can move the cursors 902 aand 902 b within the display screen 900 by inputting the movementinstruction of the cursor 902 a to the endoscope apparatus.

The display position of the cursor 902 a is set on the basis of theinstruction that the user inputs to the endoscope apparatus. When thecursor 902 a is set in the left image 901L, the matching process ofcalculating the position of a corresponding point on the right image901R corresponding to the display position of the cursor 902 a isexecuted. The position of the corresponding point becomes the displayposition of the cursor 902 b. In addition, an image in which asurrounding region of the cursor 902 a is enlarged is displayed in azoom window 903 a, and an image in which a surrounding region of thecursor 902 b is enlarged is displayed in a zoom window 903 b. JapaneseUnexamined Patent Publication First Publication No. 2009-86553 disclosesan endoscope apparatus which displays the same zoom windows as describedabove.

SUMMARY OF THE INVENTION

An endoscope apparatus according to an aspect of the invention includes:an imaging portion that images a subject to generate image data; adesignation portion that designates a position in an image based on theimage data; an image processing portion that processes the image datasuch that an enlarged image obtained by enlarging an image in a secondregion including the designated position overlaps a first regionincluding the designated position designated by the designation portion;a display portion that displays the enlarged image and the image of thesubject based on the image data processed by the image processingportion and displays a cursor at the designated position on the enlargedimage; and a measurement processing portion that performs measurement onthe basis of a measurement position indicated by the cursor by using theimage data generated by the imaging portion.

The enlarged image displayed on the display portion moves according tothe movement of the cursor. A program that controls an operation of anendoscope apparatus according to an aspect of the invention causes theendoscope apparatus to execute: a step of imaging a subject to generateimage data; a step of designating a position in an image based on theimage data; a step of processing the image data such that an enlargedimage obtained by enlarging an image in a second region including thedesignated position overlaps a first region including the designatedposition that has been designated; a step of displaying the enlargedimage and the image of the subject based on the image data processed bythe image processing portion and displaying a cursor at the designatedposition on the enlarged image; and performing measurement on the basisof a measurement position indicated by the cursor by using the imagedata generated by the imaging portion. The enlarged image displayed onthe display portion moves according to movement of the cursor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating the entire configuration of anendoscope apparatus according to an embodiment of the invention.

FIG. 2 is a block diagram illustrating the internal configuration of theendoscope apparatus according to the embodiment of the invention.

FIG. 3 is a block diagram illustrating the functional configuration of aCPU provided in the endoscope apparatus according to the embodiment ofthe invention.

FIG. 4 is a flow chart illustrating the procedure of an operation of theendoscope apparatus according to the embodiment of the invention.

FIG. 5 is a flow chart illustrating the procedure of an operation of theendoscope apparatus according to the embodiment of the invention.

FIG. 6 is a flow chart illustrating the procedure of an operation of theendoscope apparatus according to the embodiment of the invention.

FIG. 7 is a flow chart illustrating the procedure of an operation of theendoscope apparatus according to the embodiment of the invention.

FIG. 8 is a flow chart illustrating the procedure of an operation of theendoscope apparatus according to the embodiment of the invention.

FIG. 9 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 10 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 11 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 12 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 13 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 14 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 15 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 16 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 17 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 18 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 19 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 20 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 21 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 22 is a view illustrating a display screen of the endoscopeapparatus according to the embodiment of the invention.

FIG. 23 is a reference view for explaining the method of calculating thethree-dimensional coordinates of a measurement point using stereomeasurement.

FIG. 24 is a view illustrating a display screen of a known endoscopeapparatus.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the invention will be described withreference to the drawings. FIG. 1 shows the configuration of anendoscope apparatus according to an embodiment of the invention. Asshown in FIG. 1, an endoscope apparatus 1 includes an endoscope 2 and anapparatus body 3 connected to the endoscope 2. The endoscope 2 includesa long and thin inserted portion 20 and an operating portion 6 forperforming an operation required in executing various kinds of operationcontrols of the entire apparatus. The apparatus body 3 includes amonitor 4 (liquid crystal display), which is a display device thatdisplays an image of a subject imaged by the endoscope 2, contents of anoperation control (for example, a processing menu), and the like, and ahousing 5 having a control unit 10 (refer to FIG. 2).

The inserted portion 20 is formed by connecting a hard tip portion 21, abent portion 22 which can be bent, for example, in the upper, lower,left, and right directions, and a flexible tube portion 23 with theflexibility sequentially from the tip side. Various kinds of opticadapters, such as a stereo optical adapter having two observation fieldsof view or a normal observation optical adapter having one observationfield of view, are freely attached to the tip portion 21 or detachedfrom the tip portion 21. In the present embodiment, when performingmeasurement, left and right images which are a pair of subject images onthe left and right sides are imaged by the stereo optical adaptercapable of imaging two subject images of the same subject.

As shown in FIG. 2, an endoscope unit 8, a CCU 9 (camera control unit),and a control unit 10 are provided in the housing 5. A proximal end ofthe inserted portion 20 is connected to the endoscope unit 8. Theendoscope unit 8 is configured to include a light source driving device,which drives a light source (LED 29) built in the tip portion 21, and abending device for bending the bent portion 22 provided in the insertedportion 20.

A imaging device 28 and the LED 29 are built in the tip portion 21. Theimaging device 28 generates an image signal by performing photoelectricconversion of a subject image formed through the optical adapter. Theimage signal output from the imaging device 28 is input to the CCU 9.The image signal is converted into a video signal (image data), such asan NTSC signal, in the CCU 9 and is then supplied to the control unit10. The LED 29 generates illumination light irradiated to the subject.In the present embodiment, the LED 29 is provided in the tip portion 21.However, the LED 29 may be disposed in the housing 5 so that theillumination light generated by the LED 29 is guided to the tip portion21 through the optical fiber. In addition, other illumination excludingthe LED may be used.

A video signal processing circuit 12 to which a video signal is input, aROM 13, a RAM 14, a card I/F 15 (card interface), a USB I/F 16 (USBinterface), an RS-232C I/F 17 (RS-232C interface), and a CPU 18 thatexecutes these various functions on the basis of a main program andperforms various controls are provided in the control unit 10.

The CCU 9 and the endoscope unit 8 are connected to the RS-232C I/F 17.In addition, the operating portion 6 which performs control andoperation instructions of the CCU 9, endoscope unit 8, and the like isconnected to the RS-232C I/F 17. When a user operates the operatingportion 6, a communication required in controlling the CCU 9 and theendoscope unit 8 is performed on the basis of the operation.

The USB I/F 16 is an interface for electrically connecting the controlunit 10 and a personal computer 31 with each other. By connecting thecontrol unit 10 with the personal computer 31 trough the USB I/F 16,various kinds of instruction controls, such as an instruction to displayan endoscope image at the side of the personal computer 31 or imageprocessing at the time of measurement can be performed. In addition,input and output of various kinds of control information or data, whichis required for processing, between the control unit 10 and the personalcomputer 31 can be performed.

In addition, a memory card 32 can be freely attached to the card I/F 15or detached from the card I/F 15. By mounting the memory card 32 in thecard I/F 15, capturing of data such as control processing information orimage information stored in the memory card 32 into the control unit 10or recording of data such as control processing information or imageinformation into the memory card 32 can be performed according to thecontrol of the CPU 18.

In order to display a mixed image obtained by mixing an endoscope imagebased on the video signal supplied from the CCU 9 with an operation menuusing a graphic, the video signal processing circuit 12 performsprocessing for mixing a graphic image signal based on the operationmenu, which is generated by the control of the CPU 18, with the videosignal from the CCU 9, processing required for display the mixed imageon the screen of the monitor 4, and the like and supplies the displaysignal to the monitor 4. In addition, the video signal processingcircuit 12 may also perform processing for simply displaying anendoscope image or an image of an operation menu, independently.Accordingly, the endoscope image, the operation menu image, or the mixedimage obtained by mixing the endoscope image with the operation menuimage is displayed on the screen of the monitor 4.

The CPU 18 controls an operation of the entire endoscope apparatus 1 byexecuting a program stored in the ROM 13 in order to control variouscircuit portions to perform desired processings. The CPU 18 uses the RAM14 as a working area for temporarily storing data.

FIG. 3 shows the functional configuration of the CPU 18. A cursorposition designating portion 41 (designating portion) designates aposition (cursor position) at which a cursor is displayed in the imagedisplayed on the monitor 4, on the basis of the result when the user hasoperated a cursor moving switch of the operating portion 6. An enlargedimage generating portion 42 (image processing portion) generates data ofan enlarged image obtained by enlarging an image in a predeterminedregion including the cursor position designated by the cursor positiondesignating portion 41. A graphic processing portion 43 generates agraphic image signal for displaying on the display screen various kindsof information displayed by characters, numeric values, etc., the iconof a cursor, and the like.

A matching processing portion 44 performs matching processing forcalculating a position of a corresponding point on a right imagecorresponding to the cursor position on a left age designated by thecursor position designating portion 41. A measurement processing portion45 executes processing for calculating the three-dimensional coordinateson the basis of the principle of triangulation or measurement processingfor calculating the length, area, and the like of the subject. A maincontrol portion 46 controls assignment of processing to each of thecursor position designating portion 41, the enlarged image generatingportion 42, the graphic processing portion 43, the matching processingportion 44, and the measurement processing portion 45, and controls theoverall operation of the endoscope apparatus 1.

Next, the basic principle of the measurement in the present embodimentwill be described. FIG. 23 shows the positional relationship between twoleft and right images on the three-dimensional spatial coordinate systemwith x, y, and z axes. FIG. 23 shows a state where a point P, which isan object for measuring a distance (object distance) to the subject, isimaged on a right imaging surface 28R and a left imaging surface 28L ofthe imaging device 28. In FIG. 23, it is assumed that points OR and OLare main points of the optical system, a distance f is a focal length,points QR and QL are image locations of the point P, and a distance L isthe distance between the point OR and the point OL. In FIG. 23,expression (1) is obtained from the straight line QR-OR.

x/xR={y−(L/2)}/{yR−(L/2)}=z/(−f)   (1)

In addition, expression (2) is obtained from the straight line QL-OL.

x/xL={y+(L/2)}/{yL+(L/2)}=z/(−f)   (2)

The three-dimensional coordinates of the point P are obtained by solvingthe expression for x, y and z. As a result, the distance (objectdistance) from the point OR or the point OL to the subject iscalculated. In addition, the three-dimensional length or thethree-dimensional area can be calculated by calculating thethree-dimensional coordinates of the point P for a plurality ofmeasurement points and performing various operations using thethree-dimensional coordinates.

Next, the display screen (display portion) of the present embodimentwill be described. FIG. 9 shows a display screen 100 at the start of ameasurement mode. A pair of left and right images 101L and 101R withparallax, date and time information 103, measurement operationinformation 104, message information 105, magnifying power information106, cursors 108 a and 108 b, and the like are displayed on the displayscreen 100.

The display screen 100 is configured to include a display region, whichis provided in an I-shape in upper, lower, and middle parts of thescreen of the display portion 4, and two approximately rectangulardisplay regions excluding the I-shaped display region. A left image 101Lis displayed in the left display region shown in the drawing, and aright image 101R is similarly displayed in the right display region. Thedate and time information 103 is displayed in the lower part of theI-shaped display region. The measurement operation information 104, themessage information 105, the magnifying power information 106, objectdistance information 107 (FIG. 12), and the like are displayed in themiddle part of the I-shaped display region. The cursor 108 a isdisplayed on the left image 101L so as to overlap the left image 101L,and the cursor 108 b is displayed on the right image 101R so as tooverlap the right image 101R.

The measurement operation information 104 displays the type ofmeasurement operation, such as the distance between two points, thedepth, the area, or the angle. The present embodiment describes themeasurement operation of the distance between two points beingperformed.

The message information 105 displays information on the operation ormeasurement as various kinds of text information or numericalinformation. For example, in FIG. 9, operation guidance (example: “PUTM1” means input of a measurement point of a first point) is displayed.

The magnifying power information 106 displays the magnifying power ofimage displayed in a zoom window which will be described later.

The cursors 108 a and 108 b are used to input a measurement point on thedisplay screen 100 The position of the cursor 108 a is calculated by thecursor position designating portion 41 according to the operation inputfrom the cursor moving switch of the operating portion 6. The positionof the cursor 108 b is calculated by the matching processing portion 44on the basis of the position of the cursor 108 a.

When the zoom switch of the operating portion 6 is operated and displayof the zoom window is instructed, zoom windows 109 a and 109 b aredisplayed as shown in FIG. 10 The zoom window 109 a is displayed in theleft image 101L, and the zoom window 109 b is displayed in the rightimage 101R.

The cursor 108 a and an enlarged image, which is obtained by enlargingan image within a predetermined range around the cursor 108 a in theleft image 101L, are displayed in the zoom window 109 a. The cursor 108b and an enlarged image, which is obtained by enlarging an image withina predetermined range around the cursor 108 b in the right image 101R,are displayed in the zoom window 109 b. The size of each of the zoomwindows 109 a and 109 b is 60×60 pixels, for example. When themagnifying power is 2×, enlarged images obtained by enlarging, forexample, images within the range of 30×30 pixels on the left and rightimages 101L and 101R are displayed in the zoom windows 109 a and 109 b,respectively. The shapes of the cursors 108 a and 108 b displayedtogether with the zoom windows 109 a and 109 b may be different fromthose of the cursors 108 a and 108 b when the zoom windows 109 a and 109b are not displayed.

The user can change the magnifying power of the enlarged image displayedin each of the zoom windows 109 a and 109 b by operating the zoom switchof the operating portion 6. The zoom switch is configured to include ateleswitch for enlargement and a wide switch for reduction. Themagnifying power is increased when the teleswitch is operated in a statewhere the zoom windows 109 a and 109 b are displayed. In addition themagnifying power is decreased when the wide switch is operated in astate where the zoom windows 109 a and 109 b are displayed. When themagnifying power is 1×, the zoom windows 109 a and 109 b are notdisplayed.

In addition, the user can move the zoom windows 109 a and 109 b togetherwith the cursors 108 a and 108 b by operating the cursor moving switchof the operating portion 6. For example, when an instruction to move thecursor 108 a downward is input from the state of FIG. 10 the zoomwindows 109 a and 109 b move downward together with the cursors 108 aand 108 b, as show in FIG. 11. In order to reduce the processing load ofthe endoscope apparatus 1, the zoom windows 109 a and 109 b are notdisplayed during the movement of the cursor 108 a. The zoom windows 109a and 109 b are displayed when the cursor 108 a stops.

Hereinafter, the transition of the display screen will be describedusing the point-to-point measurement as an example. In thepoint-to-point measurement, a first measurement point and a secondmeasurement point are set and the distance between the two points iscalculated on the basis of the two measurement points.

When the user performs an operation of deciding a measurement point withthe cursor moving switch of the operating portion 6 in a state where thecursor 108 a is displayed at the desired position at which the userwants to set a first measurement point, the first measurement point isset at a position within a region of the zoom window 109 a, for example,at the position where the cursor 108 a is displayed. Second overlayinformation, such as the first measurement point, is set on the basis offirst overlay information, such as the zoom window 109 a or the cursor108 a. Moreover, on the display screen, the first overlay informationmay move with respect to the second overlay information. FIG. 12 shows astate where the cursor 108 a and the zoom window 109 a have moved withrespect to the first measurement point after the first measurement pointwas set on the basis of the zoom window 109 a. A first measurement point110 a is displayed on the left image 101L, and a corresponding point 110b corresponding to the measurement point 110 a is displayed on the rightimage 101R. When the measurement point 110 a is set, the zoom windows109 a and 109 b become not to be displayed. If necessary, the user maydisplay the zoom windows 109 a and 109 b again as shown in FIG. 12 byoperating the zoom switch of the operating portion 6.

In addition, when the measurement point 110 a is set, the objectdistance is calculated and the object distance information 107 isdisplayed. The object distance information 107 indicates the degree ofthe distance between the tip portion 21 of the inserted portion 20 andthe subject. This object distance is calculated by the measurementprocessing portion 45. The object distance is expressed by nine squareindicators, and a smaller number of square indicators are displayed asthe object distance becomes smaller.

Image matching information may be displayed instead of the objectdistance information. The image matching information indicates thematching degree between a designated position of one image (in thisexample, the left image 101L) input by the examiner and thecorresponding position of the other image (in this example, the rightimage 101R). This matching degree is calculated by the matchingprocessing portion 44. The matching degree is expressed by nine squareindicators, and a smaller number of square indicators are displayed asthe matching degree becomes stronger (as images at the designatedposition further match each other).

In addition, although object distance information 107 is expressed bythe square indicators in this example, it may be expressed by numericvalues or in other forms.

Then, when the user performs an operation of deciding a measurementpoint with the cursor moving switch of the operating portion 6 in astate where the cursor 108 a is displayed at the desired position atwhich the user wants to set a second measurement point, the secondmeasurement point is set at the position where the cursor 108 a isdisplayed. When the second measurement point is set, the distancebetween the two points is calculated and displayed on the display screen100 as a measurement result.

FIG. 13 shows a state where the second measurement point is set. Asecond measurement point 111 ais displayed on the left image 101L, and acorresponding point 111 b corresponding to the measurement point 111 ais displayed on the right image 101R. In addition, measurement resultinformational 112 indicating the result of the point-to-pointmeasurement is displayed in the middle part of the I-shaped displayregion. In addition, a measurement line 113 which connects themeasurement point 110 a and the measurement point 111 a is displayed onthe left image 101L.

When the measurement point 111 a is set, the zoom windows 109 a and 109b become not to be displayed. If necessary, the user may display thezoom windows 109 a and 109 b again as shown in FIG. 13 by operating thezoom switch of the operating portion 6. Moreover, in the point-to-pointmeasurement of the present embodiment, the point-to-point measurementmay be performed again by setting the first and second measurementpoints again in a state where the measurement points 110 a and 111 a andthe corresponding points 110 b and 111 b are displayed after thedistance between two points is calculated and the measurement resultinformation 112 is displayed. Accordingly, the cursors 108 a and 108 band the zoom windows 109 a and 109 b can move with respect to themeasurement points 110 a and 111 a, the corresponding points 110 b and111 b, and the measurement result information 112.

Next, an operation of the endoscope apparatus 1 will be described withreference to the flow chart. FIG. 4 shows the overall operation of theendoscope apparatus 1. When the endoscope apparatus 1 is started, themain control portion 46 executes initialization (step SA). Then, themain control portion 46 monitors a signal input from the operatingportion 6 through the RS-232C I/F 17 and determines whether or not thezoom switch for image magnification change is ON (step SB). When thezoom switch is ON, the main control portion 46 instructs themagnification change in electronic zoom processing for enlarging theimage to the video signal processing circuit 12 (step SC). Then, theprocess proceeds to step SD. In addition, when the zoom switch is OFF instep SB, the process proceeds to step SD.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a brightness switch for image brightness change is ON (step SD).When the brightness switch is ON, the main control portion 46 instructsthe brightness change of the whole image to the video signal processingcircuit 12 (step SE). Then, the process proceeds to step SF. Inaddition, when the brightness switch is OFF in step SD, the processproceeds to step SF.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a live switch for changing the measurement mode to the live mode isON (step SF). The endoscope apparatus 1 can operate in a plurality ofoperation modes (a live mode, a recording mode, a measurement mode, anda play mode). The live mode is a mode in which a moving image imaged bythe endoscope 2 is displayed in real time. The recording mode is a modein which image data imaged by the endoscope 2 is recorded in the memorycard 32. The measurement mode is a mode in which point-to-pointmeasurement or the like is executed on the basis of the image dataimaged by the endoscope 2. The play mode is a mode in which image datarecorded in the memory card 32 is read and an image of the image data isdisplayed. When the live switch is ON in a state where one of therecording mode, the measurement mode, and the play mode is operating,the main control portion 46 changes the operation mode to the live modeand instructs an operation in the live mode to each portion of theendoscope apparatus 1. Then, the imaging device 28 images a subject andgenerates an image signal. The CCU 9 converts the image signal into avideo signal. The video signal processing circuit 12 generates a displaysignal by mixing the video signal with the graphic image signal from thegraphic processing portion 43 and outputs it to the monitor 4. Themonitor 4 displays the image on the basis of the display signal (stepSG). Then, the process proceeds to step SH. In addition, when the liveswitch is OFF in step SF, the process proceeds to step SH.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a menu switch is ON (step SH). When the menu switch is ON, thegraphic processing portion 43 generates a graphic image signal foroperation menu display and outputs it to the video signal processingcircuit 12 (step SI). Then, the process proceeds to step SJ. Inaddition, when the menu switch is OFF in step SH, the process proceedsto step SJ.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot an LED switch for turning on the LED in the optical adapter is ON(step SJ). When the LED switch is ON, the main control portion 46instructs starting of a lighting device to the endoscope unit 8 (stepSK). Then, the process proceeds to step SL. In addition, when the LEDswitch is OFF in step SJ, the process proceeds to step SL.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a recording switch for image recording is ON (step SL). When therecording switch is ON, the main control portion 46 changes theoperation mode to the recording mode and records image data acquiredfrom the video signal processing circuit 12 in the memory card 32 troughthe card I/F 15 (step SM). Details of step SM will be described later.Then, the process proceeds to step SN. In addition, when the recordingswitch is OFF in step SL, the process proceeds to step SN.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a play switch for image play is ON (step SN). When the play switchis ON, the main control portion 46 changes the operation mode to theplay mode, reads image data from the memory card 32 through card I/F 15,and outputs it to the video signal processing circuit 12 (step SO).Details of step SO will be described later. Then, the process proceedsto step SP. In addition, when the play switch is OFF in step SN, theprocess proceeds to step SP.

Then, the ma n control portion 46 monitors a signal input through asignal line (not shown) connected to the tip portion 21 of the insertedportion 20 and determines whether or not an optical adapter is attached(step SP). When the optical adapter is attached, the main controlportion 46 checks the type of the optical adapter, reads environmentaldata corresponding to the type from the memory card 32 through the cardI/F 15, and stores it in the RAM 14 (step SQ). Checking the type of theoptical adapter is performed by detecting the resistance value, whichchanges according to the type of the optical adapter, provided in theoptical adapter, for example. Then, the process proceeds to step SR. Inaddition, when the optical adapter is not provided in step SP, theprocess proceeds to step SR.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a measurement switch for stereo measurement is ON (step SR). Whenthe measurement switch is ON, the main control portion 46 changes theoperation mode to the measurement mode and makes each functional portionof the CPU 18 execute stereo measurement (step SS). Details of step SSwill be described later. Then, the process proceeds to step ST. Inaddition, when the measurement switch is OFF in step SR, the processproceeds to step ST.

Then, the main control portion 46 monitors a signal input from theoperating portion 6 through the RS-232C I/F 17 and determines whether ornot a power switch for a power source is ON (step ST). When the powerswitch is OFF, the endoscope apparatus 1 ends the operation. Inaddition, when the power switch is ON in step ST, the process returns tostep SB.

Next, the details of the above-described step SS (stereo measurement)will be described. The point-to-point measurement is exemplified below.FIGS. 5 to 7 show the procedure of stereo measurement. First,initialization processing is executed (step SS1). In the initializationprocessing, various variables stored in the RAM 14 are initialized. Thevarious variables stored in the RAM 14 include a variable indicating adisplay/non-display state of a zoom window, a variable indicating thecurrent cursor position, a variable indicating a state ofdecision/non-decision of a measurement point, a variable indicating theposition of the decided measurement point, and the like. Moreover, theinitialization processing is performed such that the display screen formeasurement is displayed on the monitor 4 but the zoom window is notdisplayed (for example, FIG. 9).

Then, the main control portion 46 determines whether or not the zoomwindow is displayed referring to the zoom window state variable storedin the RAM 14. Then, the main control portion 46 monitors a signal inputfrom the operating portion 6 through the RS-232C I/F 17 and determineswhether or not the zoom switch is ON (step SS2).

When the zoom window is not displayed and the zoom switch is ON,processing for displaying the zoom window is executed (step SS3).Details of step SS3 will be described later. By execution of theprocessing of step SS3, the zoom window is displayed on the displayscreen (for example, FIG. 10). By the processing of step SS3, the zoomwindow state variable in the RAM 14 is updated to the value indicating‘display’. The process proceeds to step SS4 after step SS3. In addition,when the zoom switch is displayed in step SS2 or when the zoom switch isOFF in step SS2, the process proceeds to step SS4.

In step SS4, the main control portion 46 determines whether or not thezoom window is displayed and whether or not the zoom switch is ONsimilar to step SS2 (step SS4). When the zoom window is displayed andthe zoom switch is OFF, processing for making the zoom window notdisplayed is executed (step SS5). By the processing of step SS5, thezoom window state variable in the RAM 14 is updated to the valueindicating ‘non-display’. The process proceeds to step SS6 after stepSS5. In addition, when the zoom switch is not displayed in step SS4 orwhen the zoom switch is ON in step SS4, the process proceeds to stepSS6.

FIG. 5 shows that the processing of steps SS2 to SS5 is executed betweensteps SS1 and SS6. However, when interruption occurs by the operation ofthe zoom switch of the operating portion 6, the processing of steps SS2to SS5 is executed at any processing timing of FIGS. 5 to 7. After theprocessing of steps SS2 to SS5 ends, processing is resumed from thestate immediately before the processing of steps SS2 to SS5 is executed.

In step SS6, the main control portion 46 monitors a signal input fromthe operating portion 6 through the RS-232C I/F 17 and determineswhether or not the cursor moving switch is ON (step SS6). When thecursor moving switch is OFF, the process proceeds to step SS12. Inaddition, when the cursor moving switch is ON, the main control portion46 determines whether or not the zoom window is displayed referring tothe zoom window state variable stored in the RAM 14 (step SS7).

When the zoom window is not displayed, processing for moving the cursoron the display screen is executed (stop SS8). Details of the processingof step SS8 will be described below. The cursor position designatingportion 41 calculates the next cursor position by adding the movementamount, which is designated by the operation of the cursor movingswitch, to the current cursor position referring to the current cursorposition stored in the RAM 14. The calculated next cursor position isstored in the RAM 14 as the current cursor position.

The matching processing portion 44 calculates the position of acorresponding point on the right image corresponding to the ‘next cursorposition’ on the left image by matching processing using image patternmatching. The graphic processing portion 43 generates a graphic imagesignal for displaying the icon of a cursor and the like. The videosignal processing circuit 12 generates a display signal by mixing thegraphic image signal with the video signal from the CCU 9 such that thecursors are displayed at the position on the left image designated bythe cursor position designating portion 41 and the position on the rightimage calculated by the matching processing portion 44, and outputs itto the monitor 4. The monitor 4 displays an image on the basis of thedisplay signal.

As a result the cursor is displayed together with the image of thesubject imaged by the endoscope 2. While movement of the cursor is beinginstructed by the cursor moving switch, the above processing isrepeatedly executed and the cursor moves on the display screen. When theinput of the instruction to move the cursor is stopped, the processproceeds to step SS12.

When the zoom window is displayed in step SS7, processing for making thezoom window not displayed is executed (step SS9). Then, similar to stepSS8, processing for moving the cursor on the display screen is executed(step SS10). While movement of the cursor is being instructed by thecursor moving switch, the processing described in step SS10 isrepeatedly executed and the cursor moves on the display screen. When theinput of the instruction to move the cursor is stopped, the processproceeds to step SS11.

In step SS11, processing for displaying the zoom window is executedsimilar to step SS3 (step SS11). Details of step SS11 will be describedlater. By execution of the processing of step SS11, the zoom window isdisplayed on the display screen. The process proceeds to step SS12 afterstep SS11.

In step SS12 shown in FIG. 6, the main control portion 46 monitors asignal input from the operating portion 6 through the RS-232C I/F 17 anddetermines whether or not there has been the input of a decision switchfor deciding a first measurement point (step SS12). When the firstmeasurement point is not decided (decision switch is not input), theprocess proceeds to step SS16. In addition, when the first measurementpoint has been decided (decision switch has been input), the maincontrol portion 46 determines whether or not the zoom window isdisplayed referring to the zoom window state variable stored in the RAM14 (step SS13).

When the zoom window is not displayed, the process proceeds to stepSS15. In addition, when the zoom window is displayed, processing formaking the zoom window not displayed is executed (step SS14). Then,object distance calculating processing for calculating the objectdistance is executed (step SS15).

Details of the processing of step SS15 will be described below. Thematching processing portion 44 calculates the position of acorresponding point on the right image, which corresponds to theposition of the measurement point on the left image stored in the RAM14, by matching processing using image pattern matching. The measurementprocessing portion 45 calculates the three-dimensional coordinates(coordinates of the point P of FIG. 23) on the basis of the positions ofthe measurement point and corresponding point. The measurementprocessing portion 45 calculates the object distance on the basis of thecalculated three-dimensional coordinates. The object distance is adistance from the tip of the endoscope to the subject to be observed(object to be observed). For example, the object distance is calculatedas a distance from the imaging device or the objective optical system tothe subject to be observed. The calculated object distance is displayedon the display screen (for example, FIG. 12). The process proceeds tostep SS16 after step SS15.

In step SS16, the main control portion 46 monitors a signal input fromthe operating portion 6 through the RS-232C I/F 17 and determineswhether or not there has been the input of a decision switch fordeciding a second measurement point (step SS16). When the secondmeasurement point is not decided (decision switch is not input), theprocess proceeds to step SS21. In addition, when the second measurementpoint has been decided (decision switch has been input), the maincontrol portion 46 determines whether or not the zoom window isdisplayed referring to the zoom window state variable stored in the RAM14 (step SS17).

When the zoom window is not displayed, the process proceeds to stepSS19. In addition, when the zoom window is displayed, processing formaking the zoom window not displayed is executed (step SS18). Then,similar to step SS15, object distance calculating processing forcalculating the object distance is executed (step SS19).

Then, measurement processing is executed (step SS20). Details of theprocessing of step SS20 will be described below. The measurementprocessing portion 45 calculates the distance between two points on thebasis of the three-dimensional coordinates of the first measurementpoint calculated in step SS15 and the three-dimensional coordinates ofthe second measurement point calculated in step SS19. The calculateddistance between two points is displayed on the display screen (forexample, FIG. 13). The process proceeds to step SS21 after step SS20.

In step SS21, the main control portion 46 determines whether or not toend the stereo measurement (step SS21). For example when the instructionto end the stereo measurement has been input, the stereo measurementends. In addition, when the stereo measurement is not ended, the processreturns to step SS2.

Details of the processing of step SS3 and SS11 will be described below(FIG. 7). The enlarged image generating portion 42 extracts data, whichcorresponds to an image in a predetermined region (for example, a regionof 30×30 pixels) on the left image around the cursor position designatedby the cursor position designating portion 41, from the image dataacquired from the video signal processing circuit 12. In addition, theenlarged image generating portion 42 extracts data, which corresponds toan image in a predetermined region (for example, a region of 30×30pixels) on the right image around the corresponding point on the rightimage corresponding to the cursor position on the left image, from theimage data acquired from the video signal processing circuit 12. Inaddition, the enlarged image generating portion 42 executes imageenlarging processing on the basis of the extracted data to generate dataof the left and right enlarged images (step SS31).

The video signal processing circuit 12 processes the image data so thatthe left enlarged image generated by the enlarged image generatingportion 42 overlaps the predetermined region (for example, a region of60×60 pixels) on the left image around the cursor position designated bythe cursor position designating portion 41. Specifically, the videosignal processing circuit 12 executes processing for rewriting data ofthe image data, which corresponds to the image in the predeterminedregion (for example a region of 60×60 pixels) on the left image, to thedata of the left enlarged image. In addition, the video signalprocessing circuit 12 processes the image data so that the rightenlarged image generated by the enlarged image generating portion 42overlaps the predetermined region (for example, a region of 60×60pixels) on the right image around the position of the correspondingpoint on the right image corresponding to the cursor position designatedby the cursor position designating portion 41. Specifically, the videosignal processing circuit 12 executes processing for rewriting data ofthe image data, which corresponds to the image in the predeterminedregion (for example, a region of 60×60 pixels) on the right image aroundthe corresponding point on the right image, to the data of the rightenlarged image (step SS32). As a result, the left and right enlargedimages overlap the images of the subject imaged by the endoscope.

Then, the video signal processing circuit 12 generates a display signalby mixing the graphic image signal from the graphic processing portion43 with the image data processed in step SS32. The graphic image signalincludes the icon of a cursor, the frame of a zoom window, and the like.When the measurement point has been decided, the graphic image signalalso includes the icon of the decided measurement point and the icon ofthe corresponding point. In addition, the main control portion 46controls the video signal processing circuit 12 on the basis of thecursor position designated by the cursor position designating portion 41and the corresponding point of the cursor position calculated by thematching processing portion 44, such that the video signal processingcircuit 12 mixes the image data and the graphic image signal so that thecursors are displayed at the cursor position designated by the cursorposition designating portion 41 and the corresponding point. The monitor4 displays an image on the basis of the display signal generated by thevideo signal processing circuit 12 (step SS33). As a result, the zoomwindow and the like are displayed on the display screen.

In the processing shown in FIGS. 5 to 7, when the movement of a cursoris instructed while the zoom window is displayed, the zoom window is notdisplayed. However, it may be performed as follows. For example, thezoom window may not be displayed when the duration of a state where thecursor moving switch of the operating portion 6 is ON is 0.1 second ormore, and the zoom window may move with the cursor while displayed whenthe duration of the state where the cursor moving switch is ON is lessthan 0.1 second.

In addition, in the processing shown in FIGS. 5 to 7, the measurementprocessing is executed after the second measurement point is decided.However, after the first measurement point is decided, the measurementprocessing may also be executed before the second measurement point isdecided. In addition, in the processing shown in FIGS. 5 to 7, theobject distance calculating processing is executed after the measurementpoint is decided. However, the distance measurement processing may bealways executed irrespective of whether or not the measurement point hasbeen decided.

In addition, when it is determined that the matching degree between themeasurement point on the left image and the corresponding point on theright image is low in steps SS3 and SS11, the zoom window on the rightimage may not be displayed. Moreover, also when the corresponding pointon the right image is located outside the right measurement region as aresult of matching using the matching processing portion 44, the zoomwindow on the right image may not be displayed.

Next, a control when the zoom window overlaps other parts in the displayscreen will be described. Within the left measurement region where theleft image is displayed and the right measurement region where the rightimage is displayed, first overlay information, such as the zoom window109 a or 109 b which can move on the left image or right image, ispreferentially displayed over second overlay information, such as themeasurement points 110 a or 111 a, the corresponding points 110 b and111, and the measurement line 113, when the first overlay informationoverlaps the second overlay information. Here, when the zoom window andthe measurement point overlap each other, the zoom window ispreferentially displayed over the measurement point. For example, whenthe zoom windows 109 a and 109 b have moved near the measurement point110 a and the corresponding point 110 b from the state of FIG. 13, thezoom windows 109 a and 109 b are displayed and the measurement point 110a and the corresponding point 110 b are not displayed as shown in FIG.14. In this case, the graphic processing portion 43 does not generate agraphic image signal of the measurement points and the measurement linewithin the region where the zoom window is displayed.

The viewability of the zoom window is maintained by displaying thewindow preferentially over the measurement point as described above.

In the outside of the left measurement region where the left image isdisplayed and the right measurement region where the right image isdisplayed, third overlay information, such as the date and timeinformation 103, the measurement operation information 104, the messageinformation 105, the magnifying power information 106, the objectdistance information 107, and the measurement result information 112, isdisplayed preferentially over the first overlay information. Here, theother information is displayed preferentially over the zoom window. Forexample, when the zoom window 109 a has moved to the right end of theleft measurement region and the zoom window 109 b has moved to the rightend of the right measurement region from the state of FIG. 12, theshapes of the zoom windows 109 a and 109 b change as shown in FIG. 15.For this reason, the zoom windows 109 a and 109 b do not overlapinformation, such as the object distance information 107. The firstoverlay information is displayed preferentially over the second overlayinformation, and the third overlay information is displayedpreferentially over the first overlay information.

In the above case, if a predetermined region on the left image aroundthe cursor position designated by the cursor position designatingportion 41 protrudes from the left measurement region, the enlargedimage generating portion 42 changes the shape of the predeterminedregion such that the predetermined region does not protrude from theleft measurement region. In addition, if a predetermined region on theright image around the corresponding point of the cursor positioncalculated by the matching processing portion 44 protrudes from theright measurement region, the enlarged image generating portion 42changes the shape of the predetermined region such that thepredetermined region does not protrude from the right measurementregion. The predetermined region is a region which is set as a regionwhere the zoom window is displayed. The enlarged image generatingportion 42 generates data of the enlarged image corresponding to thepredetermined region the shape of which has been changed. In addition,the graphic processing portion 43 generates the graphic image signalobtained by changing the shape of the frame of the zoom window accordingto the change of the shape of the predetermined region. At this time,the frame of the zoom window shows a region where a measurement pointcan be input on the original image.

The visibility of information, such as the measurement result ismaintained by displaying the zoom window preferentially over theinformation displayed outside the measurement region as described above.However, the shape of the zoom window may not be changed except for thecase where the zoom window protrudes from the right end of the leftmeasurement region or the case where the zoom window protrudes from theleft end of the right measurement region. For example, it may be likeFIG. 16. At this time, the zoom windows 109 a and 109 b may not bedisplayed when the cursors 108 a and 108 b are located outside themeasurement region.

Next, another example of the display screen of the present embodimentwill be described. FIG. 17 shows a display screen 120 at the start ofmeasurement. A pair of left and right images 121L and 121R withparallax, measurement operation information 122, an enlargement icon123, a reduction icon 124, magnifying power information 125, measurementresult information 126, object distance information 127, cursors 128 aand 128 b, and the like are displayed on the display screen 120.

The display screen 120 is configured to include a display region, whichis provided in the I-shape in upper, lower, and middle parts of thescreen of the monitor 4, and two rectangular display regions excludingthe display region. The left image 121L is displayed in the left displayregion shown in the drawing, and the right image 121R is similarlydisplayed in the right display region. The measurement operationinformation 122, the enlargement icon 123, the reduction icon 124, themagnifying power information 125, the measurement result information126, and the object distance information 127 are displayed in the upperpart of the I-shaped display region. The cursor 128 a is displayed so asto overlap the left image 121L, and the cursor 128 b is displayed so asto overlap the right image 121R.

The measurement operation information 122 displays the kind ofmeasurement operation, such as the distance between two points, thedepth, the area, and the angle. In the present embodiment, it is shownthat the measurement operation of the distance between two points isperformed.

The enlargement icon 123 is for raising the magnification of an imagedisplayed in the zoom window to be described later. The reduction icon124 is for lowering the magnification of the image displayed in the zoomwindow. The magnifying power information 125 shows the magnifying powerof the image displayed in the zoom window.

The measurement result information 126 displays the measurement result,such as point-to-point measurement. Before measurement processing isexecuted, the measurement result is not displayed on the measurementresult information 126. The object distance information 127 shows thedegree of the object distance. Before object distance calculatingprocessing is executed, the object distance is not displayed on theobject distance information 127.

The cursors 128 a and 128 b are used to input a measurement point on thedisplay screen 120. The position of the cursor 128 a is calculatedaccording to the operation input from the cursor moving switch of theoperating portion 6 by the cursor position designating portion 41. Theposition of the cursor 128 b is calculated on the basis of the positionof the cursor 128 a by the matching processing portion 44. The cursor128 a changes to the arrow in the outside of the left measurement regionwhere the left image 121L is displayed. The magnifying power of theimage displayed in the zoom window can be changed by operating theenlargement icon 123 and the reduction icon 124 with this arrow.

When the zoom switch of the operating portion 6 is operated and displayof the zoom window is instructed, zoom windows 129 a and 129 b aredisplayed as shown in FIG. 18. The zoom window 129 a is displayed in theleft image 121L, and the zoom window 129 b is displayed in the rightimage 121R.

The cursor 128 a and an enlarged image, which is obtained by enlargingan image within a predetermined range around the cursor 128 a in theleft image 121L, are displayed in the zoom window 129 a. The cursor 128b and an enlarged image, which is obtained by enlarging an image withina predetermined range around the cursor 128 b in the right image 121R,are displayed in the zoom window 129 b. The size of each of the zoomwindows 129 a and 129 b is 60×60 pixels, for example. When themagnifying power is 2×, the enlarged images obtained by enlarging, forexample, images within the range of 30×30 pixels on the left and rightimages 121L and 121R are displayed in the zoom windows 129 a and 129 b,respectively.

The user can change the magnifying power of the enlarged image displayedin each of the zoom windows 129 a and 129 b by operating the enlargementicon 123 and the reduction icon 124. The magnifying power is increasedwhen the enlargement icon 123 is operated in a state where the zoomwindows 129 a and 129 b are displayed. In addition, the magnifying poweris decreased when the reduction icon 124 is operated in a state wherethe zoom windows 129 a and 129 b are displayed. When the magnifyingpower is 1×, the zoom windows 129 a and 129 b are not displayed. Inaddition, the user can move the zoom windows 129 a and 129 b togetherwith the cursors 128 a and 128 b by operating the cursor moving switchof the operating portion 6.

Hereinafter, the transition of the display screen will be describedusing the point-to-point measurement as an example. When the userperforms an operation of deciding a measurement point with the cursormoving switch of the operating portion 6 in a state where the cursor 128a is displayed at the desired position at which the user wants to set afirst measurement point, the first measurement point is set at theposition where the cursor 128 a is displayed. FIG. 19 shows a statewhere the first measurement point is set. A first measurement point 130a is displayed on the left image 121L, and a corresponding point 130 bcorresponding to the measurement point 130 a is displayed on the rightimage 121R. When the measurement point 130 a is set the object distanceis calculated and the object distance information 127 is displayed.

Then, when the user performs an operation of deciding a measurementpoint with the cursor moving switch of the operating portion 6 in astate where the cursor 128 a is displayed at the desired position atwhich the user wants to set a second measurement point, the secondmeasurement point is set at the position where the cursor 128 a isdisplayed. When the second measurement point is set, the distancebetween the two points is calculated and displayed on the display screen120 as a measurement result.

FIG. 20 shows a state where the second measurement point is set. Asecond measurement point 131 a is displayed on the left image 121L, anda corresponding point 131 b corresponding to the measurement point 131 ais displayed on the right image 121R. In addition, the measurementresult information 126 indicating the result of the point-to-pointmeasurement is displayed. In addition, a measurement line 133 whichconnects the measurement points 130 a and 131 a to each other isdisplayed. Moreover, in the point-to-point measurement of the presentembodiment, even after the distance between two points has beencalculated and the measurement result information 126 is displayed, thepoint-to-point measurement may be performed again by setting new firstand second measurement points in a state where the measurement points130 a and 131 a and the corresponding points 130 b and 131 b aredisplayed.

In the transition of the display screen shown in FIGS. 17 to 20, it isassumed that reducing the processing load of the endoscope apparatus 1is not essential. Accordingly, the zoom windows 129 a and 129 b aredisplayed even during the movement of the cursors 128 a and 128 b.Moreover, even after the operation of deciding the measurement points130 a and 131 a is performed, the zoom windows 129 a and 129 b aredisplayed.

Next, details of step SS (stereo measurement) when displaying thedisplay screen shown in FIGS. 17 to 20 will be described. Thepoint-to-point measurement is exemplified below. FIG. 8 shows theprocedure of stereo measurement. In FIG. 8, the same processing as theprocessing shown in FIGS. 5 and 6 is denoted by the same step number.The following explanation will be focused on a different part from theprocessing shown in FIGS. 5 and 6.

Processing of steps SS1 to SS5 is the same as the processing of stepsSS1 to SS5 of FIG. 5. When the cursor moving switch is ON in step SS6,processing for moving the cursor is executed in step SS8 while thedisplay/non-display state of the zoom window is not changed.

When the first measurement point is decided in step SS12, objectdistance calculating processing is executed in step SS15 to calculatethe object distance while the display/non-display state of the zoomwindow is not changed. In addition, when the second measurement point isdecided in step SS16, object distance calculating processing is executedin step SS19 to calculate the object distance while thedisplay/non-display state of the zoom window is not changed. Then,measurement processing is executed in step SS20 to calculate thedistance between the two points.

In the processing shown in FIG. 8, the measurement processing isexecuted after the second measurement point is decided. However, afterthe first measurement point is decided, the measurement processing maybe executed before the second measurement point is decided. In addition,in the processing shown in FIG. 8, the object distance calculatingprocessing is executed after the measurement point is decided. However,the object distance calculating processing may be always executedirrespective of whether or not the measurement point has been decided.

In addition, when it is determined that the matching degree between themeasurement point on the left image and the corresponding point on theright image is low in step SS3, the zoom window on the right image maynot be displayed.

Next, a control when the zoom window overlaps other parts in the displayscreen in transition of the display screen shown in FIGS. 17 to 20 willbe described. Within the left measurement region where the left image isdisplayed and the right measurement region where the right image isdisplayed, the second overlay information is displayed so as to beincluded in the first overlay information when the first overlayinformation which is movable on the left image or the right imageoverlaps the second overlay information. Here, when the zoom window andthe measurement point overlap each other, the measurement point isdisplayed in the zoom window. For example, when the zoom windows 129 aand 129 b have moved near the measurement point 130 a and thecorresponding point 130 b from the state of FIG. 20, the measurementpoint 130 a is displayed together with the cursor 128 a in the zoomwindow 129 a and the corresponding point 130 b is displayed togetherwith the cursor 128 b in the zoom window 129 b as shown in FIG. 21. Inaddition, the measurement line 133 is also displayed in the zoom window129 a. In addition, when the second overlay information, such as themeasurement point 130 a and the measurement line 133, is thus displayedin the zoom window which is the first overlay information, both theoriginal image and the second overlay information may be enlarged anddisplayed in the zoom window, or only the original image may be enlargedand the second overlay information may be displayed in the zoom windowwith the original size.

By displaying the measurement point and the corresponding point in thezoom window together with the enlarged image as described above, thepositions of the measurement point and corresponding point can bechecked in the zoom window.

In the outside of the left measurement region where the left image isdisplayed and the right measurement region where the right image isdisplayed, it is as follows. For example, when the zoom window 129 a hasmoved to the lower end of the left measurement region and the zoomwindow 129 b has moved to the lower end of the right measurement regionfrom the state of FIG. 20, the zoom windows 129 a and 129 b aredisplayed outside the frame of the measurement region as shown in FIG.22 if the position of the cursor 128 a is within the left measurementregion. In addition, if the position of the cursor 128 a is outside theleft measurement region, the zoom windows 129 a and 129 b are notdisplayed and the cursor 128 a changes to the arrow. If this arrow movesto the inside of the left measurement region, the cursors 128 a and 129b and the zoom windows 129 a and 129 b are displayed again.

In the above case, when the cursor position designated by the cursorposition designating portion 41 is within the left measurement region,the enlarged image generating portion 42 generates data of left andright enlarged images obtained by enlarging images in predeterminedregions on the left and right images as described above. The graphicprocessing portion 43 generates a graphic image signal such that theframe of the zoom window, the enlarged image, the measurement point, andthe like are displayed so as to overlap on the frame of the measurementregion.

In addition, the enlarged image generating portion 42 does not generatedata of the enlarged image if the cursor position designated by thecursor position designating portion 41 is outside the left measurementregion. The graphic processing portion 43 generates a graphic imagesignal including an arrow instead of the zoom window and the cursor.

On the display screen 120, information, such as a measurement resultwhich is the third overlay information, is not displayed near themeasurement regions where the left and right images are displayed.Accordingly, even if the zoom window is displayed across the measurementregion, the visibility of the information, such as the measurementresult, is not damaged. On the other hand, the visibility of the zoomwindow is maintained. The third overlay information is displayed suchthat the visibility is not damaged by the first overlay information.

As described above, in the present invention, the zoom window includingthe enlarged image around the cursor position is displayed together withthe cursor at the cursor position designated by the cursor positiondesignating portion 41, and the zoom window moves corresponding to themovement of the cursor. For this reason, problems in checking theenlarged image are reduced.

Moreover, as shown in FIG. 15, when the zoom window attempts to protrudefrom the measurement region, the visibility of information such as themeasurement result displayed outside the measurement region can bemaintained by changing the shape of the zoom window such that the zoomwindow is not displayed outside the measurement region.

In addition, as shown in FIG. 21, when the zoom window overlaps themeasurement point and the corresponding point, the positions of themeasurement point and corresponding point can be checked in the zoomwindow by displaying the measurement point and the corresponding pointin the zoom window together with the enlarged images.

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as listing. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the spirit or scope of the present invention.Accordingly, the invention is not to be considered as being limited bythe foregoing description and is only limited by the scope of theappended claims. For example, although the point-to-point measurementwas described in the stereo measurement, the control regarding thedisplay of the zoom window may also be applied for other measurements.Moreover in the above-described embodiments, the zoom window or thecursor was exemplified as the first overlay information, the measurementpoint, the corresponding point, or the measurement line was exemplifiedas the second overlay information, and the date and time information,the measurement operation information, the message information) themagnifying power information, the object distance information, or themeasurement result information was exemplified as the third overlayinformation. However, examples of the overlay information are notlimited to those described above and may be suitably changed accordingto the usage of the endoscope apparatus, the purpose of use of theendoscope apparatus, and the like. For example, when the measurementresult information is displayed on the left image, the measurementresult information may be considered as the second overlay informationinstead of the third overlay information.

According to the invention, since the enlarged image is displayed at thedesignated position together with the cursor and the displayed enlargedimage moves corresponding to the movement of the cursor, problems inchecking the enlarged image are reduced.

1. An endoscope apparatus comprising: an imaging portion that images asubject to generate image data; a designation portion that designates aposition in an image based on the image data; an image processingportion that processes the image data such that an enlarged imageobtained by enlarging an image in a second region including thedesignated position overlaps a first region including the designatedposition designated by the designation portion; a display portion thatdisplays the enlarged image and the image of the subject based on theimage data processed by the image processing portion and displays acursor at the designated position on the enlarged image; and ameasurement processing portion that performs measurement on the basis ofa measurement position indicated by the cursor by using the image datagenerated by the imaging portion, wherein the enlarged image displayedon the display portion moves according to movement of the cursor.
 2. Theendoscope apparatus according to claim 1, wherein the display portionfurther displays the measurement position, and the enlarged imagedisplayed on the display portion moves with respect to the measurementposition displayed on the display portion according to the designatedposition.
 3. The endoscope apparatus according to claim 1, wherein thedisplay portion further displays a result of the measurement performedby the measurement processing portion, and the enlarged image displayedon the display portion moves with respect to the result of themeasurement displayed on the display portion according to the designatedposition.
 4. The endoscope apparatus according to claim 1, furthercomprising: a control portion that controls the shape of the enlargedimage according to the relative position with respect to a predeterminedrange in the image based on the image data.
 5. The endoscope apparatusaccording to claim 4, wherein the control portion controls the shape ofthe enlarged image such that the enlarged image is displayed only withinthe predetermined range.
 6. The endoscope apparatus according to claim2, wherein when the designated position and the measurement positionmatch each other, the display portion displays the enlarged imagetogether with the measurement position such that the measurementposition overlaps the enlarged image.
 7. A program that controls anoperation of an endoscope apparatus, the program causing the endoscopeapparatus to execute: a step of imaging a subject to generate imagedata; a step of designating a position in an image based on the imagedata; a step of processing the image data such that an enlarged imageobtained by enlarging an image in a second region including thedesignated position overlaps a first region including the designatedposition that has been designated; a step of displaying the enlargedimage and the image of the subject based on the image data processed bythe image processing portion and displaying a cursor at the designatedposition on the enlarged image; and a step of performing measurement onthe basis of a measurement position indicated by the cursor by using theimage data generated by the imaging portion, wherein the enlarged imagedisplayed on the display portion moves according to movement of thecursor.